ORS § 547.480
The collection of the tax shall be coincident with collection of the state and county tax, and shall be governed by the laws relating thereto, except that the tax collector shall collect and account for the tax for operation and maintenance separate from the taxes levied by the district for other purposes. When paid to the county treasurer all taxes or assessments levied and collected for operation and maintenance shall be carried in a fund to be known as the operation and maintenance fund. All warrants issued in payment for operation and maintenance, as provided in ORS 547.150, shall be drawn against and paid out of this fund. The county treasurer shall make returns to the secretary of the board of supervisors, and shall pay over and account for all moneys collected thereon quarterly to the treasurer of the district.
ORS 547.480